In recent years, an augmented reality technology that performs display by adding visual information to a movie captured by a camera has been developed. An information processing apparatus such as a wearable apparatus or a tablet terminal is used in the augmented reality technology, and a head mounted display (HMD) apparatus provided with a camera is used as the wearable apparatus. Information related to an object that is present in a field of view of a user is displayed on a screen of such an information processing apparatus so as to correspond to a position of the object.
It is possible to support a work, such as maintenance checkup and machine installation in a plant, of a user by using such an augmented reality technology. Since the user performs work with their both hands in many cases, an HMD apparatus that the user can wear on their head is more suitable for supporting the user work than a tablet terminal.
Gestures including interaction with an object are used as a method of operating the HMD apparatus in some cases. As for such operations by gestures, the HMD apparatus detects that a specific operation has been performed by recognizing motion of user's hands in an image. In such a case, it is important to precisely extract a hand region from the image in order to recognize the motion of the hands.
Technologies of extracting hand regions by using distance images and various technologies related to division of image regions, plane detection, and fingertip detection are known.
As examples of related art, Japanese Laid-open Patent Publication Nos. 2014-238828, 2015-114762, and 2014-182442, Felzenszwalb et al., “Efficient Graph-Based Image Segmentation”, International Journal of Computer Vision, Vol. 59, No. 2, September 2004, Hiroshi Masuda, “Shape reconstruction technology based on laser measurement data”, Kanrin, Journal of The Japan Society of Naval Architects and Ocean Engineers, Vol. 40, January 2012, Hiroaki Iinuma et al., “High-speed algorithm for plane detection using 3D Hough Transform”, Transactions of 2013 Spring Meeting of The Japan Society for Precision Engineering, 2013, Trevor et al., “Efficient Organized Point Cloud Segmentation with Connected Components”, Semantic Perception Mapping and Exploration, May 2013, Bhuyan et al., “Fingertip Detection for Hand Pose Recognition”, International Journal on Computer Science and Engineering, Vol. 4, No. 3, March 2012, and Jang et al., “3D Finger CAPE: Clicking Action and Position Estimation under Self-Occlusions in Egocentric Viewpoint”, IEEE Transactions on Visualization and Computer Graphics, Vol. 21, No. 4, April 2015 are known.